Journey into Space

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Venus has an atmosphere that is mostly carbon dioxide and is always blanketed in brilliant white clouds. Most astronomers think its hidden surface is too hot to support the "carbon-cycle" life that exists on the earth. Mars is the best bet, but it is not too promising. U.S. Astronomer Percival Lowell, who died in 1916, spent 30 years studying the "canals" on Mars. He was convinced (and convinced a large public) that they were attempts by Martians to irrigate their arid planet with water from its polar snowcaps. Modern astronomers believe that Lowell was describing more than meets science's eye, but the Lowell hypothesis is still popular among space enthusiasts.

Poor Neighbors. In spite of imaginative efforts to make the planets sound attractive, scientists consider earth's neighborhood rather slummy. But the space planners are optimistic. Colonists on the airless moon, they say. could erect Plexiglas domes and fill them with any atmosphere they liked. They could grow bumper crops in the unfailing sunlight, could extract metals and oxygen from the rocks. Arthur C. Clarke in The Explora, tion of Space argues that man might thrive under such conditions better than he does on earth.

Astronomer Fritz Zwicky has a more ambitious scheme: an interplanetary reclamation project. Using his new tool, nuclear energy, man could improve the circumstances of underprivileged planets, change their atmosphere or even relocate them in more favorable orbits.

The Time Problem. Other stars may have better planets. But a handicap to interstellar voyages is that they must conquer not only space but time. Even the nearest stars are light-years away, and each light-year is six trillion miles. If a space ship traveled at 50,000 m.p.h. (high speed in the solar system), it would take many thousands of years to reach a nearby star. Its crew would die of old age before the voyage had really gotten under way.

One answer to the time problem is "nature's way": reproduction. Individuals die, but species need not. An interstellar breeding-ship with a male & female crew would need close population control and the careful "recycling of biological material" (i.e., eating the dead). It would also need a university on board to preserve the cultural level of the original crew. But if all went well, the generation could colonize the Pleiades.

Some interstellar space men have a more ingenious answer than this Noah's Ark method. If a space ship moves at nearly the speed of light, its time slows down. It can sail like a cosmic ray for thousands of earth-years from star to star, but for its crew only weeks will pass. When they return to earth, however, they will all be Rip Van Winkles: their friends and families will long since have passed into ancient history.

Other interstellar enthusiasts favor taking short cuts through the fourth dimension. The best way to visualize this scheme is to imagine "two-dimensional people" who spend their lives on the surface of a sheet of paper, and who cannot form any conception of the three-dimensional world. If the paper were bent into a deep U, they could not cut across from one edge to the other; they would have to go around the fold.